ES2440968T3 - ADSL and 3G traffic aggregation in local gateway environment - Google Patents

Abstract

A gateway device (9) for simultaneously connecting a device to a plurality of networks, including a primary network and a secondary network, said secondary network which is a mobile telecommunications network (12), the gateway comprising: - a plurality of modules communication (1, 2), each communication module configured to establish a connection and transfer data with a respective network, the communication module that corresponds to the primary network that is also configured to obtain an IP address to communicate with the first primary network; and - aggregation means (3) comprising: an allocation unit (7) configured to assign an IP address that is identical to the IP address obtained for the established connection of the primary network to the remaining connections; and a data exchange unit (8) configured to exchange data traffic through the networks simultaneously.

Description

ADSL and 3G traffic aggregation in local gateway environment

Field of the Invention

The present invention is comprised within the field of telecommunications, and more specifically it relates to accessibility to the data service established simultaneously via radio via mobile networks and through wired / fixed network.

Background of the invention

In cutting-edge technology, there are several solutions capable of working with both mobile and fixed technologies but still, not simultaneously. 3G and ADSL, the preferred technologies that are deployed globally, are often considered excludable. Despite this idea, there are several solutions that use 3G and ADSL in the prior art. However, 3G is merely used as an ADSL backup.

As an additional development, a company called Workman Engineering has manufactured a device - the “Ivory II Wifi Router” - that combines wireless and / or wired Internet connections into one using separate networks with different IP addresses. The combination of the two connections is achieved by multiplexing.

Another example of the prior art is US 2008019272, which describes a DS1 traffic multiplexing system through wired and wireless Ethernet devices. DS1 is a standard for transmitting voice and data. This document deals with traffic transmission especially using TDM (time division multiplex) in Ethernet systems to transmit voice traffic in conjunction with data traffic.

Existing solutions discussed above lack flexibility. In this way it would be desirable to provide customers using data services, with a device that simultaneously has fixed and mobile capabilities.

GB-2,462,939 refers to an email communications system that has a secondary wireless connection to the Internet, in case the primary connection fails. A wireless link to an access point is provided, which routes the data received through a public static IP address associated with the access point to a private static IP address.

A product marketed by Draytek as Vigor2955 is a broadband router with a dual WAN interface. A virtual private network (VPN) secure connection layer (SSL) facility is implemented.

Description of the invention

The present invention achieves this goal by establishing a procedure that allows a unique IP address for both fixed and mobile connections. This means that packets are routed through both networks.

According to the present invention, a gateway device is provided to simultaneously connect a device to a plurality of networks, including a primary network and a secondary network, said secondary network which is a mobile telecommunications network, the gateway comprising:

-

 a plurality of communication modules each communication module configured to establish a connection and transfer data with a respective network, the communication module corresponding to the primary network which is also configured to obtain an IP address to communicate with the first primary network; Y

-

aggregation means comprising:

an allocation unit configured to assign a unique IP address obtained from the established connection of the primary network to the remaining connections using the address obtained from said established connection; Y

a data exchange unit configured to exchange data traffic through networks simultaneously.

According to a further aspect of the invention a control module is provided for the gateway device comprising:

-

 a detection unit configured to calculate, for each network, packet delays and data traffic load;

-

 a regulation unit configured to regulate data traffic on each network.

Also an object of the invention is a method for aggregating data traffic on a plurality of networks, said networks including a primary network and a secondary network, said secondary network which is a mobile telecommunication network, the method comprising the steps from:

-

 establish a first connection to the primary network in order to obtain an IP address to communicate with said primary network;

-

 establish at least one secondary connection having an IP address identical to the primary connection, said secondary connection which is a connection on the secondary network, using the IP address obtained from the connection of the primary network; and

-

 exchange data traffic over the primary network and over the secondary network.

Still other features of the present invention are to provide a method for detecting, for each network, whether a congestion state is close to being reached, and regulating data traffic over the networks, by implementing a delay equalization mechanism. , in order to avoid performance degradation.

As can be seen, the present invention is based on a single IP connection, the same for both connections, each having its own way to transport traffic.

This arrangement has advantages over the prior art discussed above because it allows bandwidth to be shared between different applications that use the same public IP address and run on different paths, that is, different networks. On the contrary, prior art solutions do not use a unique IP address but an IP per network. As a result of using different IP addresses, bandwidth cannot be shared between applications. The resources that are available on one connection cannot be properly reallocated to another connection if those connections have different IP addresses.

Due to this fact, two established connections that use the same IP to transmit and receive data traffic on the respective networks, a problem arises in case such networks had different delays. This invention also provides an equalization mechanism for said delays.

For the sake of clarity, the description here refers to a single fixed connection and a single mobile connection, but the same invention can be applied in the case of several fixed networks and several mobile networks, in which the first connection that achieves an address IP is defined as the primary connection.

As an example, the following cases are considered:

•

Primary connection: ADSL; other network: 3G

•

Primary connection: ADSL; other network: LTE

•

Primary connection: ADSL; other 3G and LTE network

•

Primary connection: fixed fiber-based network; another 3G network

•

Primary connection: 3G; other network: LTE

In the text that comes the case ADSL + 3G will be the scenario considered preferred.

In addition, when it comes to this approach, it is worth considering how packet delays are handled. In particular, TCP performances can be affected when the networks involved introduce very different transmission delays, as sometimes happens, especially when the networks are of a different nature and architecture as in the case of mobile and fixed-based networks.

As indicated above, an equalization mechanism of said delays by the present invention is also addressed. A specific function is proposed to handle, in the TCP transport protocol, the different delays that packets may suffer.

Brief description of the drawings

A series of drawings that help a better understanding of the invention and that are expressly related to an embodiment of said invention, presented as a non-limiting example thereof, are described very briefly below.

Figure 1 shows an example of architecture according to the present invention.

Figure 2 shows a mobile network architecture that includes a GERAN and a UTRAN.

Figure 3 shows an embodiment according to the present invention.

Description of a preferred embodiment of the invention

A residential or local gateway (9) (HG) is a network interconnect device, used as a gateway to connect devices (10) in the home to the Internet (16) or other WAN. For example, a modem is considered an HG. In order to deliver traffic simultaneously in an efficient way across multiple networks, for example through a fixed-based network such as ADSL and a mobile network such as 3G or LTE, the proposed solution requires the local gateway (HG) using an address Single public IP for both (or all) of the multiple networks. By doing so, each TCP client application connected to the local gateway (HG) can establish a normal TCP / IP connection using a single TCP port and the client IP address. According to one feature, the local gateway (HG) will have access to two connections with the same source IP address, so both can be used simultaneously.

On the other hand, mobile networks (22, 23) require an identification of a device in the mobile network. The identification unit represents a subscriber of a service in said network (this element is the SIM in GSM or the UICC in UMTS).

Then in the transport network that interconnects the HG (9) with the Internet there will be a set of routers that will have connection with both networks (the fixed-based one, for example ADSL and the mobile).

The first Router that has the ability to reach the HG through the fixed or mobile network is called the Common Router (13). It is primarily a typical router with routing functions, connected both networks and is aware that the UE can be reachable by any path. However, according to a particular embodiment of the present invention that is suitable for certain situations, it may require that the common router (13) manage road delays.

Routers will route incoming and ongoing packets based on standard routing protocols used in the industry.

The protocols can be divided into two categories: distance-vector routing protocol and link-state routing protocol. There are many examples of routing protocols in the industry.

Examples of distance-vector routing protocol are:

•

Routing Information Protocol (RIP)

•

Interior Gateway Routing Protocol (IGRP)

•

Enhanced Interior Gateway Routing Protocol (EIGRP)

Examples of link-state routing protocols are:

•

First Shortest Open Path (OSPF)

•

Intermediate system to intermediate system (IS-IS)

Local Gateway Communication

The communication procedure with a unique public IP address covers several steps:

-

 First of all the Primary Connection (for example based on ADSL) has to be established by the HG. Once this connection is established, an IP address is assigned to the HG.

-

 After that, the HG requests the establishment of a PDP context using this same IP address as per TS 29.060-750, section 7.3.1 of the 3GPP.

The referred text is cited below:

‘If the MS requests a dynamic PDP address and a dynamic PDP address is allowed, then the PDP Address field in the End User Address information element will be empty. If the MS requests a static PDP Address then the PDP Address field in the End User Address information element will contain the static PDP address. In the event that the PDP addresses transported in the End User Address and optionally in the Protocol Configuration Option information element contain contradictory information, the PDP address transported in the End User Address information element takes the highest precedence. '

The PDP context activation request contains different parameters such as the Access Point Name (APN) and the type of address. When the parameters are properly configured, the PDP context is accepted. These tasks are performed by the allocation unit (7) on the local gateway (9).

The GPRS Gateway Support Node (17) needs to be configured considering that it is the group of IP addresses used by the DSL network. Then, such information is used when an activation of the PDP context of an IP address belonging to said group is received. The information includes an indication that this particular HG has a double connection, the PDP context is accepted in this way and all systems (for example billing systems) will be informed accordingly. When both connections are established, only the common router (s) and the HG will realize that there is more than one path (two in case of more mobile landline) to route packets to the unique IP address , the common router will always announce itself to the ISP (15) as the next hop to reach the group of static public IP addresses from the Internet. The GGSN and the BRAS / BNG do not know (and do not need to know) that there are really two connections in parallel to the HG. However, it is worth mentioning that state services such as flow-based charging, heuristic classification and reasonable use policy reinforcement will not be possible to use in the GGSN (17).

Alternatively, if 3G is established first while the ADSL network is not operational (for example due to ADSL not yet active or a temporary failure), the ADSL becomes active, the 3G connection is released and the Procedure starts as explained before.

3G connection control for congestion cases

In order to avoid congestion states, the present invention needs a control mechanism for 3G. As the 3G connection is shared among many other users, it is necessary to provide a criterion to decide how to share bandwidth. A control unit (4) is responsible for these functions in the local gateway (9).

As an example, we consider ADSL + 3G users, who have two network connections while, on the other hand, the rest of the users have only active 3G. In order to avoid congestion and provide a good quality of service to all users, it will be necessary to reduce the maximum flow to ADSL + 3G users in the 3G network.

It is not complicated to identify ADSL + 3G users (for example from their range of known dedicated IP addresses). Then the Central Network (for example the PCRF) can mark the QoS of this 3G PDP context as a low priority one and then it will not affect the rest of the "normal" 3G connections.

Delay equalization function

It is known that existing TCP connections whose packets run with different variable delays can suffer performance degradation.

Currently, the way in which the TCP protocol normally recognizes a segment loss, and therefore requires retransmission, is based on the Round Trip Time (RTT) measurement. The RTT is defined as the time between sending a TCP segment and receiving the corresponding acknowledgment. TCP implementations have different mechanisms to measure the RTT for a given TCP connection, the old TCP implementation is based on a sample measurement per window size, in this case each equal TCP will measure the time between sending a TCP segment and the receiving the corresponding recognition from the other equal and will use this value as the RTT for the total duration of the current window size, however this very often leads to an inaccurate estimate of the average RTT for the given window size.

An advanced implementation uses the time stamp TCP option to measure RTT more accurately. In this case the sending TCP equal will add the current time stamp to the TCP segments before sending them to the destination equal, and when the destination equal recognizes the reception of each of these elements, it will only need to reflect the corresponding time stamp of Return to the same source in the recognition segment, so that in the same source a simple subtraction between the current time and the reflected time stamp will reveal the RTT for each TCP segment. Then the same source can have updated and accurate RTT values for the RTT connection.

When different networks (for example 3G and ADSL, or LTE and ADSL or even 3G and LTE) are used simultaneously as access networks and TCP as transport protocol, it is very likely that an equal TCP (or on the side of the client or server) measure the RTT based on the fastest access link delay (for example the ADSL), this will occur if a TCP segment and its recognition follow the same fast path (ADSL), the probability that This happens is 25% in a random environment.

We refer to the RTT measured in this case as RTT A. In a less critical but more likely case, an equal TCP (either on the client side or on the server side) measures the RTT based on a combination of the delays of Fast and slow links, this will happen if a TCP segment and its recognition follow the opposite paths (ADSL and 3G), the probability of this happening is 50% in a random environment. We refer to the RTT measured in this case as RTT B.

When RTT A is used, TCP segments that cross the slowest access link (3G) could be mistakenly lost by the receiving equal, for the reason that it takes longer than RTT to send a TCP segment and receive its recognition when the slowest link is used in either or both directions, this will occur in 75% of cases. When RTT B is used, only TCP acknowledgments that traverse the slowest access link (3G), while the 'recognized' TCP segment has also traversed the slowest access link (3G) could be considered erroneously lost by the Likewise, for the reason that it takes longer than RTT B to send a TCP segment and receive recognition, both on the slowest link, this will occur in 25% of cases.

The above scenarios will cause a probability of 0.25 * 0.75 + 0.5 * 0.25 = 31.25% of TCP retransmissions and, even worse, drastic reductions in the size of the congestion window that will adversely affect the maximum flow end to end

In order to deal with these scenarios, a detection unit (5) included in the control module (4) is proposed to handle different delays that may occur according to the two paths that the data packets follow. The aforementioned detection unit (5) requires a function that implements two modes of operation in order to equalize the delays experienced by the packets when going through the different networks.

The delays need to be equalized if the difference in the average RTT between the two networks is greater than a configurable threshold "X". This can serve as an event to trigger the actions performed by the function.

The function is assigned in the detection unit (5) of the HG or in the common IP router. See Figures 1 and 3.

The function implements two modes of delay equalizers:

1) Artificial delays to be introduced either in the HG or in the Common Router:

The local gateway would receive / send packets through each of the networks. The local gateway in each PDP context configured on the radio can evaluate the RTT of ADSL and the Mobile Network by sending a series of pings.

If the measured delay difference is greater than "X", the local gateway will link the packets by drifting from the network with less RTT (Fast Network) in order to introduce an artificial delay and equalize the average RTT seen by TCP or UDP clients.

For each local gateway connection, an RTT assessment should be carried out and an artificial delay added if necessary. In order to avoid a degradation of performance and congestion, a regulation unit (6) controls the flow of data on each path.

A set of criteria can be established to assess the opportunity to keep artificial retardation active:

•

One criterion is to maintain a continuous artificial delay, with a periodic revaluation (for example twice a day) of the appropriate delay.

•

Another criterion is based on an artificial delay with adjustments:

The artificial delay shall be maintained provided that the maximum downlink or uplink network flow with the highest RTT (called Slow Network) contributes significantly to the maximum total flow achieved in the downlink or uplink through the local gateway.

Every “Z” seconds the local gateway measures the maximum current flow and compares the percentage of maximum flow transported by the Slow Network to a downlink threshold and / or an uplink threshold Y_DL and Y_UL.

If the percentage is less than Y_DL and Y_UL, and if the Mobile Network is the Slow Network, the correction over the Mobile Network will be terminated.

Note that the mechanism mentioned above for delay equalization can be executed on the Common IP Router. In this case, it is only necessary to have the function on one of the devices (HG or common router).

2) TCP recognition through the opposite path

In order to equalize the difference in delay between ADSL and 3G, each TCP recognition segment is forced to follow the opposite path compared to the corresponding ‘recognized’ TCP segment. By doing this, it is ensured that the measured RTT delay (and the actual one) is always a combination of the slow and fast link delay.

This mode requires the common IP router (13) to track each uplink TCP segment sequence number and ensure that the corresponding downlink recognition segment is routed to the opposite access network, compared to the segment of uplink

The local gateway also needs to track each downlink TCP segment sequence number and ensure that the corresponding uplink recognition segment is routed to the opposite access network, compared to the downlink segment.

Therefore, this second option needs implementation in both the common IP router (13) and the HG (9). In the latter, it is carried out by means of the regulation unit (6).

GLOSSARY

It is well known that abbreviations and acronyms are frequently used in the field of mobile telephony. Below is a glossary of acronyms / terms used throughout this specification: 3GPP The ADSL 3rd Generation Cooperation Project BNG Asymmetric Digital Subscriber Line BRAS Broadband Network Gateway DSL Broadband Remote Access Server Digital Subscriber Line GERAN Access Network Radio EDGE GSM GPRS General GGSN Packet Radio Service Support Node / GPRS Service MS Gateway OSPF Mobile Station First Shortest Open Road PCRF Policy and Charging Rules Function PDP Data Protocol for IP Packages RTT Internet Protocol Roundtrip Time SIM Subscriber Identity Module TCP UICC Transmission Control Protocol UTRAN Universal Integrated Circuit Card UMTS Terrestrial Radio Access Network List of reference numbers

one

Wired communication module.

2

Radio communication module

3

Means of aggregation.

4

Control module.

5

Delay measurement unit.

6

Data flow and congestion controller.

7

Assignment Unit

8

Data exchange unit.

9

Gateway device.

10

User equipment

eleven

ADSL network.

12

Mobile Network.

13

Common router.

14

Node B.

fifteen

Company Network

8

16

Internet.

17

GGSN

18

Hlr

19

MSC

5

twenty RNC

twenty-one

PCU

22

UMTS radio network

2. 3

GSM radio network

10

Claims (15)

A gateway device (9) for simultaneously connecting a device to a plurality of networks, including a primary network and a secondary network, said secondary network which is a mobile telecommunications network (12), the gateway comprising: 5 - a plurality of communication modules (1, 2), each communication module configured to establish a connection and transfer data with a respective network, the communication module corresponding to the primary network that is also configured to obtain an IP address to communicate with the first primary network; Y

-

 aggregation means (3) comprising:

10 an allocation unit (7) configured to assign an IP address that is identical to the IP address obtained for the established connection of the primary network to the remaining connections; Y a data exchange unit (8) configured to exchange data traffic through the networks simultaneously.

2.

The gateway device according to claim 1, characterized in that it further comprises 15 - a control module (4) comprising

a detection unit (5) configured to calculate, for each network, the packet delays and the load of data traffic; a regulation unit (6) configured to regulate data traffic on each network.

3.

The gateway device according to claim 1 or 2, wherein at least the primary network is a wired network 20 based on a technology selected from:

-

 xDSL,

-

ADSL,

-

VDSL,

-

Fiber; 25 and the mobile telecommunications network is based on a technology selected from:

-

 UMTS,

-

 GSM,

-

 LTE based on FDD,

-

 LTE based on TDD, 30 - Advanced LTE.

4. The gateway device according to claim 2, characterized in that the regulation unit (6) regulates data traffic, establishing priority levels based on at least one of the following criteria: - packet delays of each network,

-

 load of each network, 35 and combinations thereof.

5. The gateway device according to claim 2, characterized in that the detection unit (5) is arranged to measure the average RTT difference between the networks and determine whether to trigger, depending on a configurable safety threshold (X), a delay equalization mechanism to avoid performance degradation. 40 6. A method for aggregating data traffic over a plurality of networks, said networks including a primary network and a secondary network, said secondary network which is a mobile telecommunication network (12), the method comprising the steps of :

-

 establish a first connection to the primary network in order to obtain an IP address to communicate with said

primary network; 10

-

 establish at least one secondary connection having an IP address identical to the primary connection, said secondary connection which is a connection over the secondary network, using the IP address obtained from the primary network connection; Y

-

 configure the primary network and the secondary network to allow the exchange of data traffic over the primary and secondary networks 5 simultaneously.

7. The method for aggregating data traffic on different networks according to claim 6, characterized in that it further comprises the steps of - detect, for each network, if a congestion state is close to being reached, and

-

 regulate data traffic over networks, through an implementation of a 10-delay equalization mechanism, in order to avoid performance degradation.

8. The method for aggregating data traffic on different networks according to claim 6 or 7, characterized in that the step of establishing a secondary connection comprises: - request the establishment of a PDP context using the IP address of the primary connection,

-

 activate the PDP context via the mobile radio network in dependence on previous information in order to obtain a valid IP address for at least one radio connection.

9. The method according to claim 6 or 7, wherein the primary network is a wired network based on a technology selected from:

-

 xDSL,

-

ADSL (11),

20 - VDSL, and the mobile radio network is based on a technology selected from:

-

 UMTS (22),

-

 GSM (23),

-

 LTE based on FDD, 25 - LTE based on TDD,

- Advanced LTE. 10. The method for aggregating data traffic on different networks according to claims 7 and 9, characterized in that the step of detecting a congestion state further comprises:

-

 send packets and receive acknowledgments of said packets over the wired network in order to estimate an average RTT 30 (RTT A) for that network,

-

 send packets and receive acknowledgments of said packets over at least one mobile radio network in order to estimate an average RTT (RTT B),

-

measure the difference in average RTT between the wired and each of the mobile radio networks to trigger, depending on a configurable safety threshold (X), a suitable delay equalization mechanism

35 for the network that has the lowest RTT value in order to regulate data traffic and avoid performance degradation. 11. The method for aggregating data traffic over different networks according to claim 10, characterized in that the delay equalization mechanism comprises:

-

 produce an artificial delay by gluing the packets from the network that has a lower RTT, and delivering

40 after a wait time is reached, the wait time that is calculated based on RTT differences to maintain a delay similar to the network that has the largest RTT. 12. The method for aggregating data traffic on different networks according to claim 11, characterized in that the delay equalization mechanism further comprises:

-

 establish, for the uplink and downlink channels of the network having the highest RTT, a contribution threshold (Y_DL, Y_UL) representing a percentage of the maximum flow with respect to the total maximum flow,

-

 periodically estimate the maximum flow for the downlink and uplink channels and compare with their respective maximum flow threshold (Y_DL, Y_UL) in order to determine whether a significant contribution is achieved for at least one of the channels, and

5 - maintain the artificial delay, encoding packets for networks that have lower RTT, provided that the contribution of the network that has the greater RTT is significant. 13. The method for aggregating data traffic on different networks according to claim 12, characterized in that the step of regulating data traffic comprises:

-

 release a connection to the network that has the largest RTT provided that, for its link channels

10 uplink and downlink, the maximum flow contribution threshold is not reached and said network having the largest RTT is a mobile radio network. 14. The method for aggregating data traffic on different networks according to any of claims 9 to 13, wherein the steps are performed either on the gateway device (9) or on the common router (13). 15. The method for aggregating radio and wired data traffic according to claims 7 and 9, characterized in that the packet delay detection steps further comprise:

-

 send packets via the gateway device (9) over the network of the minor RTT and receive acknowledgments of said packets via the common router over the network of the largest RTT and send packets via the gateway device (9) over the network of the largest RTT and receive acknowledgments of said packets through the common router on the network of the lowest RTT in order to achieve on average a similar RTT for all packets.

The method for aggregating data traffic on different networks according to claims 7 and 9, characterized in that the steps of detecting packet delays also comprise: sending packets via the common router over the network of the lowest RTT and receiving acknowledgments of said packets through the gateway device (9) over the network of the largest RTT and send the packets through the common router (13) over the network of the largest RTT and receive acknowledgments of said packets through the gateway device (9) 25 on the network of the lowest RTT in order to achieve on average a similar RTT for all packets. 17. The method for aggregating data traffic on different networks according to any of claims 6 to 15, characterized in that the step of regulating data traffic comprises establishing a special priority to devices with an IP address belonging to a subscriber of a wired network in order to give better quality of service to users with mobile radio connection only.